FGFS-4.1/gr-air-modes
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New parser works. TCAS untested. Extra info in print. Fixed ground_track printing error. Surface reports suppressed due to possible CPR bug. Not all code paths tested.

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This commit is contained in:
Nick Foster
2012-06-26 23:27:58 -07:00
parent b05bea9618
commit 28824cb0b2
6 changed files with 68 additions and 87 deletions
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53
python/cpr.py
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@@ -29,11 +29,10 @@ from modes_exceptions import *
latz = 15
def nbits(surface):
return 17
# if surface == 1:
# return 19
# else:
# return 17
if surface == 1:
return 19
else:
return 17
def nz(ctype):
return 4 * latz - ctype
@@ -97,18 +96,14 @@ def cpr_resolve_local(my_location, encoded_location, ctype, surface):
def cpr_resolve_global(evenpos, oddpos, mostrecent, surface):
dlateven = dlat(0, surface)
dlatodd = dlat(1, surface)
if surface is True:
scalar = float(2**19)
else:
scalar = float(2**17)
evenpos = [float(evenpos[0]), float(evenpos[1])]
oddpos = [float(oddpos[0]), float(oddpos[1])]
j = math.floor(((nz(1)*evenpos[0] - nz(0)*oddpos[0])/scalar) + 0.5) #latitude index
j = math.floor(((nz(1)*evenpos[0] - nz(0)*oddpos[0])/2**17) + 0.5) #latitude index
rlateven = dlateven * ((j % nz(0))+evenpos[0]/scalar)
rlatodd = dlatodd * ((j % nz(1))+ oddpos[0]/scalar)
rlateven = dlateven * ((j % nz(0))+evenpos[0]/2**17)
rlatodd = dlatodd * ((j % nz(1))+ oddpos[0]/2**17)
#limit to -90, 90
if rlateven > 270.0:
@@ -131,14 +126,14 @@ def cpr_resolve_global(evenpos, oddpos, mostrecent, surface):
nlthing = nl(rlat)
ni = max(nlthing - mostrecent, 1)
m = math.floor(((evenpos[1]*(nlthing-1)-oddpos[1]*(nlthing))/scalar)+0.5) #longitude index
m = math.floor(((evenpos[1]*(nlthing-1)-oddpos[1]*(nlthing))/2**17)+0.5) #longitude index
if mostrecent == 0:
enclon = evenpos[1]
else:
enclon = oddpos[1]
rlon = dl * (((ni+m) % ni)+enclon/2**nbits(surface))
rlon = dl * (((ni+m) % ni)+enclon/2**17)
if rlon > 180:
rlon = rlon - 360.0
@@ -172,8 +167,6 @@ def range_bearing(loc_a, loc_b):
bearing += 360.0
rnge = math.hypot(distance_East,distance_North)
return [rnge, bearing]
class cpr_decoder:
@@ -203,32 +196,30 @@ class cpr_decoder:
#okay, let's traverse the lists and weed out those entries that are older than 15 minutes, as they're unlikely to be useful.
self.weed_poslists()
if surface==1:
validrange = 45
else:
validrange = 180
if icao24 in self.lkplist:
#do emitter-centered local decoding
[decoded_lat, decoded_lon] = cpr_resolve_local(self.lkplist[icao24][0:2], [encoded_lat, encoded_lon], cpr_format, surface)
self.lkplist[icao24] = [decoded_lat, decoded_lon, time.time()] #update the local position for next time
elif ((icao24 in self.evenlist) and (icao24 in self.oddlist) and abs(self.evenlist[icao24][2] - self.oddlist[icao24][2]) < 10):
elif (icao24 in self.evenlist) \
and (icao24 in self.oddlist) \
and (abs(self.evenlist[icao24][2] - self.oddlist[icao24][2]) < 10) \
and (surface == 0):
newer = (self.oddlist[icao24][2] - self.evenlist[icao24][2]) > 0 #figure out which report is newer
[decoded_lat, decoded_lon] = cpr_resolve_global(self.evenlist[icao24][0:2], self.oddlist[icao24][0:2], newer, surface) #do a global decode
[decoded_lat, decoded_lon] = cpr_resolve_global(self.evenlist[icao24][0:2], self.oddlist[icao24][0:2], newer, surface) #do a global decode
self.lkplist[icao24] = [decoded_lat, decoded_lon, time.time()]
else:
raise CPRNoPositionError
#so we really can't guarantee that local decoding will work unless you are POSITIVE that you can't hear more than 180nm out.
#this will USUALLY work, but you can't guarantee it!
# elif self.my_location is not None: #if we have a location, use it
# [local_lat, local_lon] = cpr_resolve_local(self.my_location, [encoded_lat, encoded_lon], cpr_format, surface) #try local decoding
# [rnge, bearing] = range_bearing(self.my_location, [local_lat, local_lon])
# if rnge < validrange: #if the local decoding can be guaranteed valid
# self.lkplist[icao24] = [local_lat, local_lon, time.time()] #update the local position for next time
# [decoded_lat, decoded_lon] = [local_lat, local_lon]
#elif surface == 1 and self.my_location is not None:
# [local_lat, local_lon] = cpr_resolve_local(self.my_location, [encoded_lat, encoded_lon], cpr_format, surface) #try local decoding
# [rnge, bearing] = range_bearing(self.my_location, [local_lat, local_lon])
# if rnge < validrange: #if the local decoding can be guaranteed valid
# self.lkplist[icao24] = [local_lat, local_lon, time.time()] #update the local position for next time
# [decoded_lat, decoded_lon] = [local_lat, local_lon]
else:
raise CPRNoPositionError
if self.my_location is not None:
[rnge, bearing] = range_bearing(self.my_location, [decoded_lat, decoded_lon])